scholarly journals Ductile Compressive Behavior of Biomedical Alloys

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 60
Author(s):  
Christian Affolter ◽  
Götz Thorwarth ◽  
Ariyan Arabi-Hashemi ◽  
Ulrich Müller ◽  
Bernhard Weisse

The mechanical properties of ductile metals are generally assessed by means of tensile testing. Compression testing of metal alloys is usually only applied for brittle materials, or if the available specimen size is limited (e.g., in micro indentation). In the present study a previously developed test procedure for compressive testing was applied to determine the elastic properties and the yield curves of different biomedical alloys, such as 316L (two different batches), Ti-6Al-7Nb, and Co-28Cr-6Mo. The results were compared and validated against data from tensile testing. The converted flow curves for true stress vs. logarithmic strain of the compressive samples coincided well up to the yield strength of the tensile samples. The developed compression test method was shown to be reliable and valid, and it can be applied in cases where only small material batches are available, e.g., from additive manufacturing. Nevertheless, a certain yield asymmetry was observed with one of the tested 316L stainless steel alloys and the Co-28Cr-6Mo. Possible hypotheses and explanations for this yield asymmetry are given in the discussion section.

1978 ◽  
Vol 14 (3) ◽  
pp. 269-272 ◽  
Author(s):  
J. F. M. Fennell

SUMMARYThe use of a durometer to assess hardness of onion bulbs is described, and compared with the use of a tensile testing machine. Results from the two tests were closely correlated, and significant varietal differences were detected in bulb hardness by both machines. The durometer is of particular value because of the simplicity and non-destructive nature of the test procedure.


2013 ◽  
Vol 690-693 ◽  
pp. 2371-2378
Author(s):  
Wei Pu Xu ◽  
Yi Ting Liu

A brief overview is given in the conventional domed bursting disc structure and manufacturing method. 316L stainless steel as a template is selected. With the investigation on bursting disc material tensile test method, the test results are summarized,also the burst results of disc burst pressure in different sizes. With the help of bursting disc material performance test and bursting disc burst pressure test of 316L , the test results provide a reference for other types of bursting disc.


1985 ◽  
Vol 22 (4) ◽  
pp. 592-599
Author(s):  
R. G. Horvath

A multiple loading testing method is suggested, which permits testing a single drilled pier foundation under three different conditions of load support. The pier may be tested under conditions of combined shaft and end-bearing resistance, end-bearing resistance only, and shaft resistance only. The advantages of this multiple loading test method include observation of the load-transfer and displacement behaviours of the pier under these three different support conditions and verification of the values obtained for the components of load support, i.e., shaft and end-bearing resistance, all from a single test pier.A special base load cell capable of performing a different function during each cycle of loading is required. A suitable load cell, consisting of a series of Freyssi flatjacks, and the method of operation are described.A multiple loading test procedure was used successfully as part of a field investigation program on full-scale pier sockets in weak shale. Data on the load-displacement behaviour of the pier tested using the multiple loading method are reported. Information concerning piers tested using conventional single loading methods are provided for comparison.The multiple loading test results were in good agreement with results obtained from conventional testing methods. Thus the multiple loading test method provides an economical means of obtaining a large amount of design information for drilled pier foundation systems, using a single test pier. Key words: field load test, multiple loading, drilled piers and caissons, shaft resistance, end-bearing resistance, combined shaft and end-bearing resistances, base load cell, shale.


2019 ◽  
Vol 4 (1) ◽  
pp. 41-55 ◽  
Author(s):  
Jan Hummel ◽  
Dietmar Göhlich ◽  
Roland Schmehl

Abstract. We have developed a tow test setup for the reproducible measurement of the dynamic properties of different types of tethered membrane wings. The test procedure is based on repeatable automated maneuvers with the entire kite system under realistic conditions. By measuring line forces and line angles, we determine the aerodynamic coefficients and lift-to-drag ratio as functions of the length ratio between power and steering lines. This nondimensional parameter characterizes the angle of attack of the wing and is varied automatically by the control unit on the towed test bench. During each towing run, several test cycles are executed such that mean values can be determined and errors can be minimized. We can conclude from this study that an objective measurement of specific dynamic properties of highly flexible membrane wings is feasible. The presented tow test method is suitable for quantitatively assessing and comparing different wing designs. The method represents an essential milestone for the development and characterization of tethered membrane wings as well as for the validation and improvement of simulation models. On the basis of this work, more complex maneuvers and a full degree of automation can be implemented in subsequent work. It can also be used for aerodynamic parameter identification.


2006 ◽  
Vol 321-323 ◽  
pp. 1539-1542
Author(s):  
Wae Gyeong Shin ◽  
Soo Hong Lee ◽  
Young Sik Song

Reliability of automotive parts has been one of the most interesting fields in the automotive industry. Especially small DC motor was issued because of the increasing adoption for passengers’ safety and convenience. For several years, small DC motors have been studied and some problems of a life test method were found out. The field condition was not considered enough in the old life test method. It also needed a lot of test time. For precise life estimation and accelerated life test, new life test procedure was developed based on measured field condition. First, vibration condition on vehicle and latent force on fan motor shaft were measured and correlated with each other. Second, test condition was decided by obtained data. Finally, life of fan motors was estimated by new life test method in shorter test time.


Author(s):  
Santoshkumar R. Mulik ◽  
Rishikesh S. Bachhav

Assay analytical test procedure at the Bulk-Solution stage for Esomeprazole Sodium Injection 40mgas a Critical Processing Parameters during manufacturing developed and validated. As per current available literature and the references, Esomeprazole active substance is available in market in the five forms, i.e. Esomeprazole as Plain [Tablet]; Esomeprazole Magnesium Trihydrate [Tablet, Capsule Delayed Release]; Esomeprazole Potassium [Tablet and Capsule]; Esomeprazole Strontium [Capsule Delayed Release] and Esomeprazole Sodium [Injectable].Assay test procedure for Active and other dosage forms [Tablet, Capsule] were available based on either Potentiometric Titration or HPLC basis. Product Esomeprazole Sodium Injection 40mg is not available in official pharmacopeia. As per available reference and literature assay test method for intermediate testing and finished product is based on HPLC. Intermediate testing [In-Process Testing] required as Critical Process Parameters [CPP] to ensure the quality i.e. appropriate bulk-solution purity, before to proceed for filtration and filling of Bulk-solution in unit dosage form [Vials]. To test the bulk solution purity approximate 5-6 hours required by HPLC. Which leads to hold the Bulk solution, further it impact and may risk to Bio-Burden of bulk solution. Also it impact and reduce the productivity of line by 5-6 hours. HPLC testing required special skilled manpower and cost. Considering all above concerns Study carried for test method development based on UV-Spectroscopy, HPLC and potentiometric titration. Based on method validation performed for UV-Spectrometry, HPLC and potentiometric titration; Test procedure developed and validated based on UV-Spectrometry is found Simple, Accurate, Precise, Economical and Rapid to save time and cost with increase in productivity as a Critical Processing Parameters for Esomeprazole Sodium Injection 40mgat the Bulk-Solution stage during manufacturing.


2020 ◽  
Vol 10 (9) ◽  
pp. 3284 ◽  
Author(s):  
Bin Xie ◽  
Jiaxiang Xue ◽  
Xianghui Ren ◽  
Wei Wu ◽  
Zhuangbin Lin

Adopting the cold metal transfer plus pulse (CMT + P) process, 316L stainless steel wire was treated with a single channel multi-layer deposition experiment under different linear energy. The microstructures of different regions on the deposited samples were observed by optical microscope and scanning electron microscope, and the element distribution in the structure was analyzed by energy dispersive spectrometer. The mechanical properties and microhardness were measured by tensile test method and microhardness tester, respectively, and the anisotropy of tensile strength in horizontal and vertical directions were calculated. Finally, the fracture morphology of the tensile samples were observed by SEM. Experiment results showed that when the difference between the actual and the optimal wire feeding speed matching the specific welding speed was too large, this led to an unstable deposition process as well as flow and collapse of weld bead metal, thus seriously deteriorating the appearance of the deposition samples. The results from metallographic micrograph showed that rapid heat dissipation of the substrate caused small grains to generate in the bottom region of deposition samples, then gradually grew up to coarse dendrites along the building direction in the middle and top region caused by the continuous heat accumulation during deposition. Tensile test results showed that with the increase of linear energy, the horizontal and vertical tensile strength of the as-deposited samples decreased. In addition, the higher linear energy would deteriorate the microstructure of as-deposited parts, including significantly increasing the tendency of oxidation and material stripping. The microhardness values of the bottom, middle and top regions of the samples fluctuated along the centerline of the cross-section, and the values showed a trend of decreasing first and then rising along the building direction. Meanwhile, the yield strength and tensile strength of each specimen showed obvious anisotropy due to unique grain growth morphology. On the whole, the results from this study prove that CMT+P process is a feasible MIG welding additive manufacturing method for 316L stainless steel.


2019 ◽  
Vol 5 (1) ◽  
pp. 461-463
Author(s):  
Finja Borowski ◽  
Sebastian Kaule ◽  
Stefan Siewert ◽  
Klaus-Peter Schmitz ◽  
Michael Stiehm ◽  
...  

AbstractThe implantation of an occluder in the left atrial appendage (LAA) is an emerging therapy for the treatment of patients suffering from atrial fibrillation and with a contraindication to oral anticoagulation. The LAA occluder (LAAO) provides a reduction of the potential risk of strokes by thromboembolism. Currently, only a few CE-approved devices are available on the market and the number of clinical trials is comparatively low. Furthermore, there is currently no standardized test method available for testing functionality of the occluder, especially for testing safe anchorage and permeability. Therefore, the aim of this study is to establish an in vitro test method to prove anchorage mechanism and permeability regarding thromboembolism of the LAAO under physiological conditions. A standardized technical and fully parameterized silicone model of a LAA, based on studies of different morphologies and sizes, was developed. The LAA model was mounted onto the left atrial chamber of a commercial pulse duplicator system to simulate physiological hemodynamic conditions. The test was performed using the Watchman device (Boston Scientific, USA; size: 31 mm). The inner implantation diameter of the LAA model was designed according to a target compression of 10% for the Watchman device in the implanted configuration. Furthermore, thrombus-like particles (n=150, d=1,7±0,05 mm) were added to represent the flushing of thrombi out of the LAA after device implantation. Within several cycles it was confirmed that no particles were washed out of the LAA model with the implanted occluder leading to a full protection against thromboembolism. It could also be shown that the occluder is firmly anchored in the LAA. Pressure measurements with sensors in the left atrium and in the LAA distal to the occluder could also show that the occluder has no influence on the pressure conditions in the LAA.


2020 ◽  
Vol 1013 ◽  
pp. 132-138
Author(s):  
L.Yu. Stupishin ◽  
S.G. Emelyeanov ◽  
E.V. Savelyeva ◽  
M.L. Moshkevich

Composite structures require the use of modern reinforcing materials combining high strength characteristics and resistance to aggressive influences with low weight. One of the promising materials for the production of reinforcing products is basalt roving. The high strength of the thread in combination with fragility imposes certain limitations on its placement in the material, and requires new approaches to the design of the reinforcing bar itself. The article investigates the strength characteristics of a composite reinforcing bar made of a basalt complex thread proposed by the authors. The features of the test procedure and the mechanical characteristics of the reinforcing material are described. The effectiveness of the applied test method developed in the process of testing reinforcing rods is shown. An increase in the tensile strength of a composite reinforcing bar based on basalt fiber is established in comparison with products from fiber and roving.


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